Esempio n. 1
0
//MomentTensor returns the moment tensor for a matrix A of coordinates and a column
//vector mass with the respective massess.
func MomentTensor(A *v3.Matrix, massslice []float64) (*v3.Matrix, error) {
	ar, ac := A.Dims()
	var err error
	var mass *mat64.Dense
	if massslice == nil {
		mass = gnOnes(ar, 1)
	} else {
		mass = mat64.NewDense(ar, 1, massslice)
		//		if err != nil {
		//			return nil, err
		//		}
	}
	center, _, err := MassCenter(A, v3.Dense2Matrix(gnCopy(A)), mass)
	if err != nil {
		return nil, errDecorate(err, "MomentTensor")
	}
	sqrmass := gnZeros(ar, 1)
	//	sqrmass.Pow(mass,0.5)
	pow(mass, sqrmass, 0.5) //the result is stored in sqrmass
	//	fmt.Println(center,sqrmass) ////////////////////////
	center.ScaleByCol(center, sqrmass)
	//	fmt.Println(center,"scaled center")
	centerT := gnZeros(ac, ar)
	centerT.Copy(center.T())
	moment := gnMul(centerT, center)
	return v3.Dense2Matrix(moment), nil
}
Esempio n. 2
0
//OnesMass returns a column matrix with lenght rosw.
//This matrix can be used as a dummy mass matrix
//for geometric calculations.
func OnesMass(lenght int) *v3.Matrix {
	return v3.Dense2Matrix(gnOnes(lenght, 1))
}